The present disclosure relates generally to providing fluid into subsea pipelines and, in some embodiments, to apparatus and methods for filling, flooding and/or hydrotesting a subsea pipeline.
Subsea pipeline flooding systems often use the external (sea) water pressure to initially drive a pig, or pig train, inside the pipeline. Typically, the pipeline initially contains air or another gas at a lower pressure than the external water pressure. During the initial flooding efforts, the air in the pipeline ahead of the pig is compressed, causing the air pressure in the pipeline forward of the pig to increase. Eventually the air pressure balances the water pressure in the pipeline and all movement stops or slows significantly.
To complete movement of the pig to the distant end of the pipeline and completely fill the pipeline with water, a boost pump is often used. The objective of filling the pipeline with water is usually to perform a hydrotest, allow the pipeline to be connected underwater to further parts of a pipeline system, or both. A hydrotest is started by pumping additional water into the pipeline with the use of one or more high pressure pump to increase the internal pipeline pressure. The hydrotest typically proves the structural integrity of the pipeline, that the pipeline is free from leaks or both.
Examples of existing skid-mounted pipeline flooding and/or hydrotesting technologies are disclosed in U.S. Pat. No. 5,927,901 to Graves, entitled “Underwater Pipeline Apparatus for Delivering a Pig Unit by Flooding of the Pipeline” and issued on Jul. 27, 1999, U.S. Pat. No. 6,840,088 C1 to Tucker et al., entitled “Subsea Vehicle Assisted Pumping Skid Packages” and issued on Jan. 11, 2005, and U.K. Patent Application Pub. No. GB2390435A filed Jan. 5, 2002 and entitled “Apparatus for and Method of Flooding and/or Pressure Testing Pipelines”, the entire contents of which are hereby incorporated by reference herein.
Presently known skid-mounted pipeline filling, flooding and hydrotesting systems and techniques are believed to have one or more drawbacks. For example, the boost pump and high pressure pump on the system are often powered and/or controlled by a remotely operated vehicle (ROV) or from a floating vessel or other structure at the surface, such as via one or more umbilicals. These requirements for external power and/or control have numerous potential disadvantages. For example, when the same system is used with different ROV's and pipelines, the power provided to the pump(s) may be uncertain, which could lead to unreliable or unpredictable performance. For another example, the need to be linked to an ROV for power and/or control prevents the host vessel from undertaking other activities in other locations. For yet another example, the need to be linked to an ROV makes the entire subsea pipeline servicing (filling, flooding or hydrotesting) operation weather dependant.
It should be understood that the above discussion is provided for illustrative purposes only and is not intended to limit the scope or subject matter of the appended claims or those of any related patent application or patent. Thus, none of the appended claims or claims of any related application or patent should be limited by the above discussion or construed to address, include or exclude each or any of the above-cited examples, features and/or disadvantages, merely because of their mention herein.
Accordingly, there exists a need for improved systems, apparatus and methods useful to assist in filling, flooding and/or hydrotesting underwater pipelines having one or more of the following features, attributes or capabilities, or one of more of the features, attributes or capabilities described or shown in, or as may be apparent from, the other portions of this patent: uses a submersible apparatus that can autonomously drive a pig, fill or hydrotest a subsea pipeline, without the need for power and/or control provided by an underwater vehicle (UV) or from the surface; includes on-board control and power capabilities; is capable of autonomously and selectively starting and stopping a boost and/or high pressure pump and controlling a boost and/or high pressure pump valve without power or control sources from a UV or via an umbilical or cable to the surface; includes a submersible, on-board control unit for controlling all functions relating to flooding and/or hydrotesting a subsea pipeline; includes an on-board control unit that monitors data from at least one flow meter and/or at least one pressure sensor and controls functioning of the valves and pumps needed for flooding and/or hydrotesting in accordance with programmable logic; includes an on-board valve power assembly configured to selectively open and close valves; includes an on-board battery configured to provide one among direct current (DC), single-phase alternating current (AC) or 3-phase AC power, and may be configured to drive a hydraulic power unit; includes any among various forms of speed control for a boost pump and/or hydrotest pump; includes a pressure relief manifold to protect the pipeline from over-pressure and reduce pressure after hydrotesting.
In some embodiments, the present disclosure involves apparatus for filling and/or flooding a subsea pipeline. The apparatus includes a submersible skid configured to be deployed to the vicinity of the pipeline and at least one fluid conduit disposed at least partially upon the skid and fluidly engageable with the pipeline. At least one pump is mounted on the skid and configured to pump fluid through the fluid conduit into the pipeline for filling and/or flooding the pipeline. At least one pump valve is disposed upon the skid and associated with the pump. At least one fluid flow meter is configured to measure the fluid flow rate in the fluid conduit. At least one control unit is disposed upon the skid and configured to control the operation of the pump and the pump valve, receive data from the fluid flow meter, and actuate the pump valve and pump at least partially based upon data from the fluid flow meter. At least one battery is associated with the skid and configured to provide sufficient power to the pump and the control unit for performing at least one among filling and flooding of the subsea pipeline without power being provided to the skid from an underwater vehicle or through a cable from the surface. In some embodiments, at least one battery is disposed on the skid and the skid is autonomously powered.
The present disclosure also includes embodiments involving an apparatus for hydrotesting a subsea pipeline which include a submersible skid configured to be deployed to the vicinity of the pipeline. At least one fluid conduit is disposed at least partially upon the skid and fluidly engageable with the pipeline. At least one pump is mounted on the skid and configured to pump fluid through the fluid conduit into the pipeline for hydrotesting the pipeline. At least one pump valve is disposed upon the skid and associated with the pump. At least one pressure sensor is configured to measure the pressure of fluid flowing into the pipeline from the fluid conduit. At least one control unit is disposed upon the skid and configured to receive data from the pressure sensor and control the operation of the pump and pump valve. At least one battery is associated with the skid and configured to provide sufficient power to The pump and the control unit for performing hydrotesting of the pipeline without power being provided to the skid from an underwater vehicle or through a cable from the surface. In some embodiments, at least one battery is disposed on the skid and the skid is autonomously powered.
In various embodiments, the present disclosure involves apparatus for autonomously controlling at least one among filling, flooding and hydrotesting a subsea pipeline. The apparatus includes a submersible skid configured to be deployed to the vicinity of the pipeline and at least one fluid conduit disposed at least partially upon the skid and fluidly engageable with the pipeline. At least one pump is mounted on the skid and configured to pump fluid through the fluid conduit into the pipeline for at least one among filling, flooding and hydrotesting the pipeline. At least one pump valve is disposed upon the skid and associated with the pump. At least one control unit is disposed upon the skid and configured to autonomously control operation of the pump valve and the pump necessary for performing at least one among filling, flooding and hydrotesting of the pipeline without involvement of an underwater vehicle or other external source for controlling functions on the skid relating thereto.
The present disclosure also includes embodiments involving a method of flooding a subsea pipeline having at least one pig disposed therein. These methods use a deployable skid and at least one battery associated with the skid and not connected to an underwater vehicle or cable extending to the surface, The skid includes a control unit, a fluid conduit connectable with the pipeline and at least one pump, pump valve and flow meter associated with the fluid conduit. These methods include lowering the skid to the sea bed and fluidly connecting the fluid conduit to the pipeline. The control unit is turned on while ensuring the pump valve is closed. A pipeline valve associated with the pipeline is opened. The natural flow of sea water is allowed through the fluid conduit into the pipeline. The control unit monitors the flow rate in the fluid conduit via the flow meter, opens the pump valve and turns on the pump. The pump valve allows the flow of fluid from the pump into the fluid conduit, and the pump pumps fluid through the fluid conduit into the pipeline. The control unit turns off the pump based upon one or more among the flow rate in the fluid conduit, the passage of a certain duration of time or when the pig reaches the distant end of the pipeline. The battery provides sufficient power to the pump and control unit for flooding the pipeline, whereby power to the skid from an underwater vehicle or cable to the surface is not required for flooding the pipeline. In some embodiment, at least one battery may be disposed on the skid.
In many embodiments, the present disclosure involves a method of flooding a subsea pipeline having at least one pig disposed therein. These methods use a deployable skid that includes a control unit, a fluid conduit connectable with the pipeline and at least one pump, pump valve and flow meter associated with the fluid conduit. In these methods, the control unit autonomously controls all operations on the skid relating to flooding of the pipeline without involvement of an underwater vehicle or other external control source for controlling operations on the skid necessary for flooding the pipeline.
The present disclosure also includes embodiments involving a method of hydrotesting a subsea pipeline. These methods use a deployable skid and at least one battery associated with the skid and not connected to an underwater vehicle or cable extending to the surface. The skid includes a control unit, a fluid conduit connectable with the pipeline and at least one high pressure pump, pump valve and pressure sensor associated with the fluid conduit. These methods include lowering the skid to the sea bed, fluidly connecting the fluid conduit to the pipeline, turning on the control unit and opening the pump valve. The pressure sensor measures the pressure of fluid flowing into the pipeline from the fluid conduit. The control unit turns on the high pressure pump, which pumps fluid through the fluid conduit into the pipeline. The control unit receives data from the pressure sensor and turns off the high pressure pump when the pressure is at or above a certain level based at least partially upon data received from the pressure sensor. The battery provides sufficient power to the pump and control unit for hydrotesting the pipeline, whereby power to the skid from an underwater vehicle or cable to the surface is not required for hydrotesting the pipeline. In some embodiment, at least one battery may be disposed on the skid.
The present disclosure also includes embodiments involving a method of hydrotesting a subsea pipeline with a deployable skid that includes a control unit, a fluid conduit connectable with the pipeline and at least one high pressure pump, pump valve and pressure sensor associated with the fluid conduit. In these methods, the control unit receives data from the pressure sensor and turns off the high pressure pump when the pressure reaches or exceeds a certain level based at least partially upon data received from the pressure sensor and autonomously controls all operations on the skid relating to hydrotesting the pipeline without involvement of an underwater vehicle other external source for controlling such operations.
Accordingly, the present disclosure includes features and advantages which are believed to enable it to advance subsea pipeline servicing technology. Characteristics and advantages of the present disclosure described above and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of various embodiments and referring to the accompanying drawings.
The following figures are part of the present specification, included to demonstrate certain aspects of various embodiments of this disclosure and referenced in the detailed description herein:
Characteristics and advantages of the present disclosure and additional features and benefits will be readily apparent to those skilled in the art upon consideration of the following detailed description of exemplary embodiments of the present disclosure and referring to the accompanying figures. It should be understood that the description herein and appended drawings, being of example embodiments, are not intended to limit the claims of this patent or any patent or patent application claiming priority hereto. On the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the claims. Many changes may be made to the particular embodiments and details disclosed herein without departing from such spirit and scope.
In showing and describing preferred embodiments in the appended figures, common or similar elements are referenced with like or identical reference numerals or are apparent from the figures and/or the description herein. When multiple figure refer to a component or feature with the same reference numeral, any description herein of the component or feature with respect to any of the figures applies equally to the other figures to the extent such description does not conflict with a description herein of the other figure(s). The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.
As used herein and throughout various portions (and headings) of this patent application, the terms “invention”, “present invention” and variations thereof are not intended to mean every possible embodiment encompassed by this disclosure or any particular claim(s). Thus, the subject matter of each such reference should not be considered as necessary for, or part of, every embodiment hereof or of any particular claim(s) merely because of such reference. The terms “coupled”, “connected”, “engaged” and the like, and variations thereof, as used herein and in the appended claims are intended to mean either an indirect or direct connection or engagement. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections.
Certain terms are used herein and in the appended claims to refer to particular components. As one skilled in the art will appreciate, different persons may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. Also, the terms “including” and “comprising” are used herein and in the appended claims in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Further, reference herein and in the appended claims to components and aspects in a singular tense does not necessarily limit the present disclosure or appended claims to only one such component or aspect, but should be interpreted generally to mean one or more, as may be suitable and desirable in each particular instance.
Referring initially to
A jumper 26 is shown connected between the skid frame 14 and the pipeline 24, as is and becomes further known. The jumper 26 may have any desired construction, configuration and operation suitable to provide a fluid connection between the system 10 and the pipeline 24. The jumper 26 may, for example, include flexible pipe and/or a loading arm with hinged joints, such as may be useful for spanning varying distances, angles and heights of the skid frame 14 relative to the pipeline 24. For another example, the jumper 26 may be a rigid pipe extending from the skid frame 14.
Still referring to the embodiment of
In this example, the jumper 26 is shown extending onto the skid frame 14 and engaging a first non-return valve 34 of the system 10. However, in other embodiments, such as shown in
The illustrated first non-return valve 34 is configured to hold the fluid pressure in the piping 32 and jumper 26 forward of the valve 34, preventing undesirable or unexpected back-flow of fluid from the pipeline 24 into the system 10 and potentially through the inlet filter 30 and into the sea. For example, the pipeline 24 may be connected by a manifold to another pipeline having a higher internal fluid pressure than that of the pipeline 24. The isolation between the two pipelines may leak, resulting in a rise in fluid pressure in the pipeline 24, causing a potential undesirable back-flow of fluid into the system 10.
Still referring to the embodiment of
The exemplary system 10 also includes at least one flow meter 40 and control unit 48. The illustrated flow meter 40 is situated and configured to measure the flow rate of fluid passing through the system 10 to the pipeline 24 and communicate such data to the control unit 48. The flow meter(s) 40 may be of any suitable type and configuration, as is or becomes further known. For example, the flow meter 40 may be of a type which water flows through or past.
The system may also include at least one pressure sensor 44. However, a pressure sensor 44 may not be included or necessary for various filling and flooding operations. The illustrated pressure sensor 44 is configured to measure the pressure of fluid passing through the system 10 to the pipeline 24 and communicate such data to the control unit 48. The pressure sensor 40 may also be of any suitable type and configuration, as is or becomes further known.
The flow meter(s) 40 and pressure sensor(s) 44 may be positioned at any suitable location on the jumper 26 or piping 32. In this embodiment, the flow meter 40 and pressure sensor 44 are shown engaged with the jumper 26. The illustrated pressure sensor 44 is positioned within the skid frame 14 as close as practical to the pipeline 24, such as to provide pressure measurements as close as possible to the fluid pressure in the pipeline 24. In other embodiments, the pressure sensor 44 may instead be located closely adjacent to the end 22 of the pipeline 24 (on the jumper 26) or on the pipeline 24 itself. Also if desired, the flow meter 40 may be positioned proximate to the pressure sensor 44, such as to simplify installation of cabling from these components to the control unit 48.
Still referring to the embodiment of
The fluid pump 64 and pump power unit 66 may be of any suitable type and configuration and disposed in any suitable location. The illustrated fluid pump 64 is a variable speed water pump of sufficient capacity to serve as a boost pump capable of moving a pig, or pig train, 42 in the pipeline 24 to the distant end thereof. It should be noted that the exemplary pig 42 is shown proximate to the end 22 of the pipeline 24 for illustrative purposes. However, the pig 42 may be positioned at different locations within the pipeline 24. In some applications, there may be no pig 42 in the pipeline 24. Thus, the inclusion of and position of the pig 42 is not limiting upon the present disclosure or appended claims.
The exemplary pump power unit 66 drives the fluid pump 64 using power from the battery 50 and based upon commands from the control unit 48. In this embodiment, the fluid pump 64 is disposed on a pump line 54 between the inlet filter 30 and the first non-return valve 34. Some potential example configurations of the pump power unit 66 are: (i) a direct-current (DC) submersible electric motor, (ii) an inverter and a single phase alternating-current (AC) submersible electric motor, (iii) an inverter or multiple synchronized inverters providing 3-phase alternating-current and a 3-phase AC submersible electric motor, and (iv) any of the above submersible electric motors driving a hydraulic power unit, which drives a hydraulic motor. When one or more inverters are used, a current-limiting device for starting the electric motor may also be used.
The pump valve 56 and valve power assembly 60 may likewise have any suitable configuration, construction and operation. In this embodiment, the pump valve 56 is configured to allow or disallow fluid flow from the fluid pump 64 through the piping 32 to the jumper 26, and assists in protecting the pump 64 from the effects of excessive differential pressure when the pipeline valve 28 is first opened. The illustrated pump valve 56 also includes an actuator (not shown), such as an electrically or hydraulically powered actuator depending upon the configuration of the valve power assembly 60.
Still referring to the embodiment of
Various other potential power supply arrangements, which may be used in the subsea pipeline servicing system 10 of
Referring back to
It is often required to treat water entering the pipeline 24 by the addition of liquids, such as chemicals used to reduce corrosion in the pipeline 24. If desired, one or more liquid injectors and reservoirs (not shown) may be included in the skid frame 14. The liquid injector(s) would be in fluid communication with the piping 32 so that the desired chemicals or other liquids could be injected into the fluid flow transmitted into the pipeline 24 from the system 10. If desired, the reservoir may contain mixed liquids, or multiple reservoirs may be used for the same or different liquids. Any suitable technology for injecting the liquid may be used. Some examples are (i) a venturi providing reduced pressure and drawing the liquid from the reservoir and (ii) one or more pumps powered by any of the power sources available in the system 10.
In the embodiment of
In some embodiments, the battery 50 may not be disposed on the skid frame 14, but instead provided in a separate unit deployed to the sea floor 18 or otherwise proximate to the skid frame 14 and electrically connected with the system 10. In yet other embodiments, one or more stand-alone batteries 58 (e.g.
Still referring to the embodiment of
Electrical equipment (e.g. motors, inverters) that may be included in the system 10 will typically generate heat during their operation. Depending upon the temperature of the sea water 20 and duration of operation of the system 10, some generation of heat may be acceptable. At other times, cooling of various components on the system 10 may be necessary or desired. Any suitable technique and equipment for cooling may be used. For example, one or more impellers (not shown) powered by any of the power sources on the system 10 may be used to move water over the outside of the component housings (not shown). For another example, one or more portion of the piping 32 may be configured so that its passes through enclosures around particular components that will be cooled when sea water flows through the piping 32.
Now referring to
In other embodiments, such as the example of
In yet other embodiments, such as the example of
The HP pump assembly 90 may have any suitable configuration and operation. In this example, the HP pump assembly 90 includes a HP fluid pump 104 and HP pump power unit 106. The illustrated HP fluid pump 104 is fluidly connected to a HP pump line 100, which fluidly communicates between the inlet filter 30 and the jumper 26. The HP fluid pump 104 may be powered similarly as described above with respect to the fluid pump 64 or any other suitable arrangement.
An example power arrangement for a system including a pump assembly 52 and HP pump assembly 90 is shown in
It may be desirable to provide flow variability or regulation for the pumps in the subsea pipeline servicing system 10. For example, when approaching the test pressure during hydrotesting, it may be desirable to use the pump(s) to reduce the fluid flow rate to control the risk of overpressure. Any suitable techniques and components using one or more pumps in the system 10 for flow regulation may be included. It should be noted that the particular flow regulation technique used may depend upon the circumstances of the particular application, such as pressure changes during the hydrotest, flow ranges for different pipeline sizes and/or the power limits of the system 10.
For example, the pump assembly 52 and/or HP pump assembly 90 may provide variable speed drive and pump capabilities. Any suitable variable speed drive arrangement may be used and controlled in any suitable manner. For example, variable pump speeds may be operated by signals from the control unit 48. Some examples of potential variable speed drive arrangements are (i) a chopper circuit with a DC submersible electric motor, (ii) a variable frequency drive inverter with a 3-phase AC submersible electric motor, (iii) either submersible electric motor of (i) or (ii) driving a hydraulic power unit, which drives a hydraulic motor, (iv) a fixed-speed AC or DC submersible motor driving a hydraulic power unit with a swash plate to vary the delivered hydraulic flow, which drives a hydraulic motor.
Referring back to
The illustrated control unit 48 may obtain power from any suitable source, such as the battery 50 or another battery dedicated to the control unit 48 via a voltage converter. In this embodiment, the control unit 48 supplies power to the flow meter 40 and pressure sensor 44 and records data. In other embodiments, the flow meter 40 may not require power from the control unit 48 or battery 50. If desired, the control unit 48 may include a subsea display to show information, such as the status of the system 10 before, during and/or after operations.
Still referring to the embodiment of
The system 10 may be configured so that data link 80 is useful for any desired purpose in connection with flooding and/or hydrotesting operations. For example, the data record for the flooding and/or hydrotesting operations may be transmitted to one or more external source via the data link 80. In some embodiments, the data record may be retrievable while the skid frame 14 is deployed on the sea bed 18 or after the skid frame 14 is returned to surface from its temporary subsea location. When the data link 80 is used during hydrotesting, for example, the engineer in charge (or other personnel) may periodically use data received through the data line 80 to check the status or review the progress of the hydrotesting operations and/or initiate the next stage. For another example, when increasing pressure during hydrotesting, it may be desirable to pause at intermediate pressures to ensure the operation is progressing as expected and no leaks in the pipeline 24 are detected. In such instances, the control unit 48 can be programmed not to initiate the pump 52 (
All components of the aforementioned embodiments of the system 10 are connected by suitable piping and cabling. Electrical equipment may be housed in pressure-resistant or pressure-compensated housings, as necessary.
An embodiment method of use of the exemplary subsea pipeline servicing system 10 of
If desired, when operation of the control unit 48 is initiated, the pump valve 56 may be in an open position to allow free flooding of all piping 32. If so, the exemplary control unit 48 thereafter closes the pump valve 56 to configure the system for initial flooding by natural underwater pressure.
In this embodiment, to flood the pipeline 24, sea water 20 flows through or past the inlet filter 30, pump bypass line 36, flow meter 40, non-return valves 70, 34, pressure sensor 44, jumper 26 and pipeline valve 28, and then flows into the pipeline 24. As the pipeline 24 behind the pig or pig train 42 is filled with water, the pig or pig train 42 moves along the pipeline 24. The exemplary control unit 48 monitors the flow rate of the water 20 passing into the pipeline 24 based upon signals from the flow meter 40. The water 20 is allowed to flow naturally into the pipeline 24 due to the prevailing hydrostatic pressure until the flow stops or reduces to an undesirable rate.
Still referring to the embodiment of
When the subsea pipeline servicing system 10 is thereafter used to hydrotest the pipeline 24, the exemplary method of operation includes additional actions. If the embodiment of
Thereafter, fluid pressure in the pipeline 24 may be progressively raised during multiple stages using the autonomous power and control of the system 10. Alternatively, each pressure stage may be initiated by external command via the data link 80, such as when an operator desires to control the timing of each stage to assess leaks or for another purpose. The maximum required hydrotest pressure may be held for any desired period, such as eight hours or more or less, depending upon the design standards of the pipeline 24. If desired, the control unit 48 may be programmed so that external monitoring is not necessary during the hold period. When the pipeline pressure has been increased sufficiently for a hydrotest, the pump 64 is stopped and the pump valve 56 closed, such as to assist in holding the pressure in the line ahead of the valve 66 and prevent back pressure into the pump assembly 52. At the end of the hydrotest, the exemplary double block valve 92 and discharge valve 94 may be used, if necessary, to release pressure through the discharge piping 98. Once the pressure is reduced to an acceptable level, the pipeline valve 28 may be closed to assist in preventing unwanted backflow from the pipeline 24.
Preferred embodiments of the present disclosure thus offer advantages over the prior art and are well adapted to carry out one or more of the objects of this disclosure. However, the present invention does not require each of the components and acts described above and is in no way limited to the above-described embodiments or methods of operation. Any one or more of the above components, features and processes may be employed in any suitable configuration without inclusion of other such components, features and processes. Moreover, the present invention includes additional features, capabilities, functions, methods, uses and applications that have not been specifically addressed herein but are, or will become, apparent from the description herein, the appended drawings and claims.
The methods that may be described above or claimed herein and any other methods which may fall within the scope of the appended claims can be performed in any desired suitable order and are not necessarily limited to any sequence described herein or as may be listed in the appended claims. Further, the methods of the present invention do not necessarily require use of the particular embodiments shown and described herein, but are equally applicable with any other suitable structure, form and configuration of components.
While exemplary embodiments of the invention have been shown and described, many variations, modifications and/or changes of the system, apparatus and methods of the present invention, such as in the components, details of construction and operation, arrangement of parts and/or methods of use, are possible, contemplated by the patent applicant(s), within the scope of the appended claims, and may be made and used by one of ordinary skill in the art without departing from the spirit or teachings of the invention and scope of appended claims. Thus, all matter herein set forth or shown in the accompanying drawings should be interpreted as illustrative, and the scope of the disclosure and the appended claims should not be limited to the embodiments described and shown herein.
This application claims priority to U.S. Provisional Patent Application Ser. No. 61/535,564 filed Sep. 16, 2011 and entitled “Apparatus and Methods for Flooding and/or Testing a Subsea Pipeline” and U.S. Provisional Patent Application Ser. No. 61/590,037 filed Jan. 24, 2012 and entitled “Modified Apparatus and Methods for Flooding and/or Testing a Subsea Pipeline”, the disclosures of which are hereby incorporated by reference herein in their entireties.
Number | Date | Country | |
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61535564 | Sep 2011 | US | |
61590037 | Jan 2012 | US |